Conjugation: the Major Metabolic Pathway of 14C-difluhenzuron in the Boll Weevil13

Abstract

The metabolic fate of 14C-diflubenzuron was studied after it was injected into Anthonomus grandis grandis Boheman. Four days posttreatment, recovery of 14C was 57.7% from treated weevils and 25% from the excreta. In the weevil, 57.3% of the 14C were recovered as unchanged diflubenzuron while 0.4% was recovered as conjugates. In the excreta, ca. 2% each of diflubenzuron and 2,6-difluorobenzamide were found and the remainder was conjugates. The total amount of conjugates was ca. 18.7%. Percentages were calculated on the basis of the total injected amount. The conjugates consist of 3 or more compounds, all of which were immediately excreted as very polar compounds. Upon acid hydrolysis, radioactive moieties from the conjugates were identified as N[[(4-chloro-2-hydroxyphenyl)amino]carbonyl]-2,6-difluorobenzamide and N-[[(4-chlorophenyl)amino ]carbonyl]-2,6-difluoro-3-hydroxybenzamide, plus 2 unknowns.